I never worry about resale value on any of my guns. I only buy. I never sell. The pad on the gun in question would not deter me from buying it for one minute. If it affects the collector interest and I could get the gun for $500 less as a result, mores the better.

Pads are useful to me to help tame recoil or lengthen pull. If I buy a gun without a pad and the LOP is too short, I wouldn't hesitate to put a nice pad on it. But I do use the leather lace on pads a fair amount too. To each his own.

Nothing the government gives you is free.